These NCERT Solutions for Class 6 Maths Chapter 1 Knowing Our Numbers Ex 1.3 Questions and Answers are prepared by our highly skilled subject experts.

## NCERT Solutions for Class 6 Maths Chapter 1 Knowing Our Numbers Exercise 1.3

Question 1.

Estimate each of the following using general rule:

(a) 730 + 998

(b) 796-314

(c) 12,904 + 2,888

(d) 28,292-21,496

Make ten more such examples of addition, subtraction and estimation of their outcome.

Answer:

(a) 730 round off to 700

998 round off to 1000

Estimated sum = 1700

(b) 796 round off to 800

314 round off to 300

Estimated sum = 500

(c) 12904 round off to 13000

2888 round off to 3000

Estimated sum = 16000

(d) 28292 round off to 28000

21496 round off to 21000

Estimated difference = 7000

Question 2.

Give a rough estimate (by rounding off to nearest hundreds) and also a closer estimate (by rounding off to nearest tens):

(a) 439 + 334 + 4317

(b) 1,08,737-47,599

(c) 8325 – 491

(d) 4,89,348-48,365

Make four more such examples

Answer:

(a) Rounding off to nearest hundreds

439 round off to 400

334 round off to 300

4,317 round off to 4,300

Estimated sum = 5,000

Again, Rounding off to nearest tens

439 → 440

334 → 330

4,317 → 4,320

∴ Closer estimate = 440 + 330 + 4,320 = 5,090

(b) Rounding off to Areas tens

= 440 + 330 + 4320 = 5090

108737 round off to 108700

47599 round off to 47600

Estimated difference = 61100

Again, Rounding off to nearest tens

1,08,734 → 1,08,730

47,599 → 47,600

∴ Closer estimate=1,08,730 – 47,600 = 61,130

(c) Rounding off to nearest tens

= 108730-47600 = 61130

8325 round off to 8300

491 round off to 500

Estimated difference = 7800

Again, Rounding off to nearest tens

8,325 → 8,330

491 → 490

∴ Closer estimate = 8,330 – 490 = 7,800

(d) Rounding off to nearest tens

= 8330 – 490 = 7840

489348 round off to 489300

48365 round off to 48400

Estimated difference = 440900

Again, Rounding off to nearest tens

4,89,348→ 4,89,300

48,365 → 48,370

Closer estimate=4,89,350-48,370=4,40,980

Question 3.

Estimate the following products using general rule:

(a) 578 x 161

(b) 5281 x 3491

(c) 1291 x 592

(d) 9250 x 29

Make four more such examples

Answer:

(a) 578 x 161

578 round off to 600

161 round off to 200

The estimated product

= 600 x 200 = 1,20,000

(b) 5281 x 3491

5281 round of to 5,000

3491 round off to 3,500

The estimated product

= 5,000 x 3,500 = 1,75,00,000

(c) 1291 x 592

1291 round off to 1300

592 round off to 600

The estimated product

= 1300 x 600 = 7,80,000

(d) 9250 x 29

9250 round off to 10,000

29 round off to 30

The estimated product

= 10,000 x 30 = 3,00,000